Jelastic PaaS provides an out-of-box integration of the fast, lightweight and highly scalable NodeJS application server. It is automatically supplied with numerous optimization and management tools to make the hosting process maximally convenient for developers.
In this article, we’ll go through the main tools and features available on the platform to provide the required level of Node.js hosting.
Node.js Environment Hosting
To run your Node.js application, you need to set up the appropriate environment using the powerful and intuitive Topology Wizard. Switch to the Node.js tab, select the required engine version for your application server and add any other software stack required. If needed, adjust other parameters, such as cloudlets and nodes count, Public IPv4 and IPv6, etc.
Note: Each instance is a completely isolated container, fully independent and uninfluenced by other stacks. Additionally, scaled out nodes are automatically distributed across the physical servers (or VMs) ensuring high availability.
For greater convenience, each NodeJS application server contains a built-in development tool called Package Manager, which provide standardization and automation of the installation, update, configuration, and removal processes.
Jelastic supports two types of package managers:
npm – manages your project requirements by installing the additional modules, packages, and ready-to-use applications
yarn – operates the same requirements as in npm (so no changes are required for the existing applications), while providing higher speed, reliability, and convenience
By default, the npm package manager is used for the NodeJS application servers, but, if necessary, it can be easily switched to yarn. For that, access the container variables frame and set the appropriate PACKAGE_MANAGER value (either npm or yarn).
Node.js Process Managers
Process Managers provide the ability to control application lifecycle, monitor running services and maintain the project operability. Jelastic PaaS provides support of the following process managers for the NodeJS stack:
pm2 – provides a huge variety of application management features, including the launched Node.js processes monitoring
forever – allows running your Node.js processes continuously and automatically restarting them upon failure
supervisor – monitors running applications for changes and automatically restarts required ones to keep them up-to-date
Users can choose the necessary process manager during container redeployment or by adjusting the PROCESS_MANAGERvariable (using forever, npm, pm2 or supervisor as value, container restart is needed to apply new options).
Your Node.js application can be easily supplemented with the custom domain name to be used instead of the default one. There are two options based on your environment topology:
CNAME redirect if using Shared Load Balancer; is recommended for dev and test environments
DNS A Record if using Public IP; can handle high traffic load and is suitable for production environments
Also, you can quickly switch traffic between your environments (e.g. to redirect customers to the newer application version without downtime) by utilizing the swap domains functionality or with the help of the SwapExtIpsAPI/CLI method.
Automatic Vertical Scaling
Jelastic PaaS dynamically provide the exact amount of resources (RAM and CPU) required by your nodes according to the current load with no manual intervention required. As a result, you never overpay for unused resources and save your time as the platform eliminates the need to handle the load-related adjustments or architectural changes.
You just need to set the upper cloudlets limit (each one equals to 128 MiB of RAM and 400 MHz of CPU) for your NodeJS application server and everything else will be handled by platform automatically.
To scale out/in NodeJS application servers, you need to access the topology wizard and click the +/- buttons within the Horizontal Scaling section to set the required number of nodes. Also, starting with the 5.5 platform version, you can adjust the preferred scaling mode:
Stateless – simultaneously creates all new nodes from the base image template
Stateful – sequentially copies file system of the master container into the new nodes
The maximum number of the same-type servers within a single environment layer depends on a particular hosting provider settings (usually this limit stands for 16 nodes and can be enlarged by sending the appropriate request to support).
Also, for the proper requests distribution, a load balancer instance is automatically added upon NodeJS server scaling. Refer to the horizontal scaling documentation for more details.
Automatic Horizontal Scaling
Access the environment Settings > Monitoring > Auto Horizontal Scaling section to set up special tunable triggers, which allow to increase or decrease the number of nodes due to the application load. Configure type of resource to be monitored (CPU, RAM, Network, Disk) and the exact condition of scaling.